Andrew D. Lee

A graphic digital database of drosophila embryogenesis

Modern studies of the genetic control of development have increased the need for an accurate and comprehensive storage and display of gene expression data. This can be achieved in the form of an electronic graphic database of development. Here, we introduce the first steps towards a database of Drosophila embryogenesis. For each morphologically defined stage, a complete series of histological and/or optical sections are generated (optical sections are generated by laser confocal microscopy). Digitized sections are imported into a drawing program where they serve as templates to define the contours of organs and the position of individual cells. From these data, surface and point cloud models of all developmental stages are generated. Gene expression data can be entered by translating the expression domain of a given gene into the three-dimensional coordinate system of the database.

MK801-induced activated caspase-3 exhibits selective co-localization with GAD67

Blockade of the N-methyl-d-aspartate receptor (NMDAR) in postnatal day 7 (P7) rats can promote rapid and robust induction of the pro-apoptotic marker activated caspase-3 (AC3) and loss of the GABAergic marker GAD67 at P56. Thus, we hypothesized that NMDAR blockade-induced AC3 occurs in GAD67 positive cells at P7. To test this idea, we injected P7 rat pups with vehicle or MK801 and after 8h (peak of AC3 induction) we examined brain sections for both AC3 and GAD67. Compared to vehicle, MK801 profoundly induced AC3 in all brain regions examined but co-expression of GAD67 in the same cells was not observed. However, in brain regions where punctate (synaptic) GAD67 was abundant (for example, layer IV of the somatosensory cortex), AC3 was robust. These data suggest that whereas somatic expression of AC3 and GAD67 may be non-overlapping, areas that exhibit punctate GAD67 (and are high in synaptic turnover) may be more vulnerable to MK801 exposure.

Acquired eruptive vellus hair cysts.

Eruptive vellus hair cysts (EVHCs) are rare epidermal cysts with vellus hairs that may be inherited or acquired. Eruptive vellus hair cysts were first identified three decades ago and are considered a developmental anomaly of follicular occlusion. Acquired EVHCs have rarely been reported. We describe a case of acquired EVHCs initially misdiagnosed as steatocystoma multiplex (SM). A 41-year-old woman presented with a three month history of a slowly progressive pruritic eruption on her chest and neck. She had been in good general health, with no pertinent past medical history. There was no family history of EVHCs. On physical examination, the patient was a thin-appearing, African–American woman. Complete dermatologic examination revealed multiple domeshaped hyperpigmented to flesh-colored papules on the upper chest and lateral neck (Fig. 1). A biopsy from a lesion on the chest revealed a cyst lined by epithelium identical to the epidermis and to the infundibulum of the hair follicle. Laminated keratin and numerous vellus hairs were present within the cyst (Fig. 2). Prior to presentation to the dermatology clinic, treatment of the pruritus with antihistamines did not provide relief. She was started on topical corticosteroids, which resulted in a mild decrease in pruritus, but the lesions remained cosmetically bothersome. Subsequently, a trial of topical 12% lactic acid daily for two months resulted in a modest improvement in the appearance of the lesions and in the pruritus. Eruptive vellus hair cysts have been a distinct dermatologic condition since they were originally described in two pediatric patients in 1977. The pathophysiology of EVHCs remains unclear, but it may be the result of a developmental anomaly leading to abnormal follicular occlusion. Evidence exists for an autosomal dominant inheritance, although EVHCs may also appear without genetic predisposition. Sporadic cases have a later age of onset compared with those with a family history of EVHCs, and lesions appear without prior trauma or irritation to the skin. Prevalence is similar among gender and race. Although the majority of cases are asymptomatic, some patients report pruritus and tenderness. Eruptive vellus hair cysts have been reported as an isolated condition but have also been linked to other medical conditions and syndromes, such as congenital pachyonychia, ectodermal dysplasia, and chronic renal failure. Eruptive vellus hair cysts and SM are clinically difficult to differentiate because of their similarity in distribution and appearance of the lesions. Patients may also share similar demographics in terms of age and inheritance patterns. Histology may prove to be equally challenging, as pilosebaceous cysts with features of both EVHCs and SM have been reported. Moreover, different lesions from the same patient may give the histologic appearance of either EVHCs or SM. Based on clinical and histologic similarities, these may be seen as two related conditions within the spectrum of pilosebaceous disorders. As such, we propose to focus on two main histologic features to Figure 2 Biopsy taken from the chest shows a cystic structure lined with squamous epithelium, filled with laminated keratin and multiple vellus hairs (hematoxylin– eosin stain; ·10 original magnification)

Postnatal expression of GAD67.

N-methyl-d-aspartate receptor blockade promotes apoptosis at postnatal day 7 (P7) and is linked to loss of glutamic acid decarboxylase 67 (GAD67) expression in older animals. To more fully appreciate this relationship we must first understand how GAD67 is regulated postnatally. Thus, the brains of P7, P14 and P21 rats were examined for expression of GAD67 protein and we found that levels of this GABAergic marker increased steadily with age, such that by P21 there was as much as a 6-fold increase compared to P7 animals and a 1.5- to 2-fold increase compared to P14 animals, depending on the region sampled. At P7, GAD67 was almost exclusively detected in puncta, with very few cell bodies displaying this marker. In contrast, at P14 and especially P21, both puncta and cell bodies were robustly labeled. Our data indicate that adult-like expression of GAD67 emerges quite late in the postnatal period.

JAAD grand roundA 70-year-old man with pruritic plaques

The use of IPL has also been studied as a treatment option for patients with facial lentigines, such as those seen in PJS. Remington et al treated a single PJS patient with IPL (47 J/cm, 3.2 msec pulse duration, 591-1200 nm) after the administration of topical lidocaine and oral sedation. There was almost complete clearance of perioral, periorbital, and nasal areas after only one treatment, but 12 treatments on separate occasions were performed because of the patient’s pain intolerance. For this series, the recommended choices are: 6, e; 7, e; 8, e; 9, a; 10, a; and 11, b.

A 70-year-old man with pruritic plaques

The use of IPL has also been studied as a treatment option for patients with facial lentigines, such as those seen in PJS. Remington et al treated a single PJS patient with IPL (47 J/cm, 3.2 msec pulse duration, 591-1200 nm) after the administration of topical lidocaine and oral sedation. There was almost complete clearance of perioral, periorbital, and nasal areas after only one treatment, but 12 treatments on separate occasions were performed because of the patient’s pain intolerance. For this series, the recommended choices are: 6, e; 7, e; 8, e; 9, a; 10, a; and 11, b.